marrow

¹ American  

[mar-oh] / ˈmær oʊ /

noun

1. Anatomy. a soft, fatty, vascular tissue in the interior cavities of bones that is a major site of blood cell production.

2. the inmost or essential part.

   to pierce to the marrow of a problem.

3. strength or vitality.

   Fear took the marrow out of him.

4. rich and nutritious food.

5. Chiefly British. vegetable marrow.

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marrow ² American  

[mar-oh, mar-uh] / ˈmær oʊ, ˈmær ə /

noun

Scot. and North England.

1. a partner; fellow worker.

2. a spouse; helpmate.

3. a companion; close friend.

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marrow ¹ British  

/ ˈmærəʊ, -rə /

noun

1. dialect a companion, esp a workmate

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marrow ² British  

/ ˈmærəʊ /

noun

1. the fatty network of connective tissue that fills the cavities of bones

2. the vital part; essence

3. vitality

4. rich food

5. short for vegetable marrow

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marrow Scientific  

/ măr′ō /

1. See bone marrow

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marrow Cultural  

1. The soft, specialized connective tissue that fills the cavities of bones. One kind of bone marrow is responsible for manufacturing red blood cells in the body.

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Other Word Forms

• marrowish adjective
• marrowless adjective
• marrowy adjective

Etymology

Origin of marrow¹

First recorded before 900; Middle English marw(e), marwa, Old English mearg, merg; cognate with Dutch merg, German Mark, Old Norse mergr

Origin of marrow²

First recorded in 1400–50; late Middle English marwe, maro(we), “fellow worker, partner,” perhaps from Old Norse margr “many; friendly”

Explanation

The soft stuff inside of a bone is called marrow. Many people cook with marrow from beef bones and consider it a delicacy. Dogs love to gnaw on bones, trying to get at the marrow inside, and many soups and other recipes call for marrow, which is tender and fatty. Human beings, of course, have marrow inside their bones as well, and certain diseases can be treated by marrow transplants. From this biological kind of marrow comes a figurative meaning of marrow — the essence of something. You might say, "This sentence represents the marrow of the novel."

Example Sentences

In fact, it is a family of cancers that originate in the bone marrow, then flow through the blood rather than form a single mass.

From The Wall Street Journal • Apr. 19, 2026

Several factors appear to drive this decline, including accumulated cellular damage, changes in gene activity, chronic low-level inflammation, and shifts in the bone marrow environment.

From Science Daily • Apr. 16, 2026

The researchers found no trace of the virus in samples of the man's blood, gut and bone marrow.

From Barron's • Apr. 13, 2026

I tend to order tartare whenever I see it, and Redbird’s version stands out: served over a crisp potato tosti with caramelized onion crema, egg jam, pickled pearl onion, and shaved marrow.

From Salon • Mar. 31, 2026

Her son was a blessing, and Laila was relieved to discover that her fears had proved baseless, that she loved Zalmai with the marrow of her bones, just as she did Aziza.

From "A Thousand Splendid Suns" by Khaled Hosseini